Temperature control attachment



July 2, .1935. L. R. CALVERT TEMPERATURE CON TROL ATTACHMENT Filed Dec.5, 1931 4 sheetsrsheet l III V lNVENTdR T A. A. C/MVZPT ATTORNE July 2,1935. r L, R, CALVERT v 2,006,567

TEMPERATURE CONTROL ATTACHMENT Filed Dec. 5, 1931 4s t -s m 2 INVENTORL. 2?. cm 1 5 r 'ATTORNEY I July 2, 1935. L. R. CALVERT TEMPERATURECONTROL ATTACHMENT Fild Dec. 5, 1931 4 Shets-Shefa s INVENTOR L R. CALVEFT /77 9 ATTORNE July 2, 1935. R. CALVERT TEMPERATURE CONTROLATTACHMENT Filed Dec. 3, 1951 4 Sheets-Sheet, 4

- INXOENTOR A. R CALI/EFT 7 ATTORNEY Patented July 2, 1935 UNITED STATESTEMPERATURE CONTROL ATTACHDIENT Landon RJCalvcrt, Newark, N. J.,assignor to Westinghouse Lamp, Company, a corporation of Pennsylvania,

Application December s, 1931, serial No. 578,717 11 Claims. ((1236-70)This invention relates to temperature control apparatus and relates moreparticularly to a coordination of machine elements to produce a positiveaction to control chemical, electrical or physical conditions andparticularly variations in temperature.

Measuring and indicating apparatus have heretofore been employed for therecording of tem perature variations but such apparatus as for examplethat shown in Reissue Patent 15,697 to H. Brewer utilizecertainelectrically operated .and operating elements which meet certainrequirements, but which in many cases do not give the necessary positiveaction. Furthermore, under certain conditions itis desirable to reduceor eliminate wiring, relays, contacts, etc., as for example, whenoperating an apparatus such as shown in my patent 1,762,156 June 10,1930. This patent shows an apparatus in which variations of temperatureaffecting a thermo-couple are transmitted through a relay and otherelectrical means to change the direction of flow of a stream of waterwhich in turn operates a fuel supply line.

It is an object of the present invention to simplify and render morepositive the apparatus shown inmy patent referred to above.

Another object is to transfer movement caused by electrical means into apositive mechanical movement.

A more specific object of the invention is to control a fluid flow inaccordance with temperature change of a heat zone by mechanical meansinterposed between the medium to be controlled and electrical meansaffected by temperature variations.

Other objects and advantages of the invention will be more clearlyunderstood from the following description together with the accompanyingdrawing in which i Fig. 1 is a diagrammatic view showing the presentinvention employed to control the length and temperature of a gas flame.

Fig. 2 is an enlarged detail view of a portion of the mechanicalconstruction for controlling the operation of a gas regulator.

Fig. 3 is a view taken on lines III-III in Fig. 2.

Fig. 4 is a fragmentary detail view showing means for controlling a flowof liquid.

Fig. 5 isa diagrammatic representation of a mercury switch arranged tobe actuated by the present mechanism.

Fig. 6 is a perspective view of the recording mechanism employed inconnection with the mechanical control means and Fig. 7 is a fragmentaryview of a modified form of the present mechanism in which the movementof a heat controlled member is amplified.

The present invention may be used in connection with variousdevices asfor example the operation of a mercury switch, or other cases where itis desirable to control a flow of electrical energy for variouspurposes. As a practical embodiment of the invention the same is shownin connection with 'an apparatus for maintaining a gas flame at adetermined length and tempera-' ture, such apparatus being shown in myabove mentioned patent. As set forth in this patent, in the manufactureof certain glass articles, where a plurality of blanks are to beconsolidated by fusing, it is necessary to employ a gas flame to softenthe parts for consolidation.

The gas flame, in order to obtain the best results, should be maintainedat a selected length and temperature, and should be held uniform. When alarge number of machines are used having many flames and when themachines are positioned over relatively great areas, it is difficultunder ordinary conditions to maintain the above desired conditions. Theflames vary in length and temperature by reason of the change inpressure in the main" gas or fluid line. Variations in the density andcomposition of the fluid fuel also occur.

Regulating means are provided in the form of a control device. Forexample a Smoot regulator may be employed to regulate the pressure butthe variations resulting from the-change in density or chemicalcomposition are not eliminated.

In the type of apparatus to which the present. invention is applied, astandard or master flame is arranged to operate an electricthermo-couple. The thcrmo-couple is so disposed with respect to a masteror standard flame that upon an,increase in the temperature or flamelength the variations in temperature are indicated on a recordinginstrument. Any suitable recording instrument may be used and thepresent invention provides mechanical elements arranged to be actuatedby the recording instrument to translate positive motion to actuatemeans for controlling a fluid flow or to actuate a movable element orswitch as for example a mercury switch to con trol the flow ofelectrical energy.

The present invention may be applied to an auxiliary or supplementalcontrol for a plurality of gas flames distributed throughout a factoryand receiving fuel from a common source. As shown in the drawings, amain Iii may receive gas supplied from a local gas producer or morefrequently from the city gas supply line.

Before the gas is passed to the machines where it is to be used in theform of flames, it is common practice to regulate the gas pressure andas shown, a pressure regulator II is provided mounted on a supportingframe or table I I. This regulator may be of any well-known type and isusually connected to the gas main by a conductor such as l2. Within theregulator is a suitably positioned diaphragm sensitive to the pressurewithin the main. The diaphragm operates to move a lever arm l3 which isconnected to a. link l4 pivoted to an arm i5 of a valve l5, which valvecontrols the inlet flow of gas. The diaphragm within the regulator maybe set so that the valve I6 will be automatically opened and closed tomaintain a given pressure of gas in that part of the main I0 whichconducts fuel.to the various machines or locations where it is to beused in the form of flames.

The pressure regulator H is usually supplied with a depending member I!which under ordinary conditions is weighted and so associated with thediaphragm as to set the same to operate the valve H5 at a givenpressure. In the present invention, the usual weights are omitted andthe diaphragm is controlled by means of a lever member. 3 in a manner tobe hereinafter more fully described.

The structure comprising the pressure. regulator, control valve, etc.,just described is -wellknown and commonly employed in connection, withgas burning systems.

As hereinbefore pointed out, however, the present invention aims to moreaccurately regulate.

the working length and temperature of the gas flames in a factoryreceiving fuel from the main Ill. The commonly used elements of thesystem have been described first for a better understanding of thefollowing detailed description of the present novel construction.

Gas entering the main it) may be distributed throughout a factory tovarious machines such as glass-working machines each machine employing aplurality of nozzles, such, for example, as 2!, the flame 22 of whichmay be directed to heat glass parts 23 and 24 to render the same plasticand fuse or unite them. When uniting delicate glass parts, as forexample, in the construction of a composite glass body such as anelectrical incandescent lamp, it is important that the flame bemaintained at a uniform length and that the heat of theflame bemaintained at a constant temperature. A fine flame of uniform length andtemperature is also of great advantage in other industries as forexample in singeing or in the production of artificial silk.

Ordinarily with a gas of a suitable density and composition, thepressure regulator should maintain the proper working conditions of theflame. Owing to the fact that the composition of the gas varies, meansare employed to compensate for suchvariation, which means may comprise amaster flame 25 which is directed against a-baflie 26 to heat the same.This baflle is constructed in an eifectiv'e and novel manner -as setforth in my Patent No. 1,762,156 issued couple is connected by leads 28and 29 to a meter measuring or indicating instrument 5| as for 'ments 46and 41.

example a galvanometer so that a fluctuation in Y the temperature of thethermo-couple will cause an oscillation of the needle or pointer 32 ofthe meter.

In accordance with the present invention the movement of the needle 32is utilized to control the operation of certain mechanical elementswhich in turn control or regulate the Smoot regulator as shown in thepresent embodiment of the invention or to control a flow of electricalenergy by operating a switch or other mechanical current controllingdevice.

-In the construction shown in my patent above mentioned, the needle 32operated between contacts to cause a flow of electrical energy through arelay to cause means to regulate the flow of gas or fuel by varying theamount of a liquid in a bucket 31 which is substituted for thecounterweights on the regulator Ii. The bucket 31 is suspended from thelever arm l8 fulcrumed at i 8'. By filling or emptying the bucket 31, avarying weight may be placed upon the arm l8 and consequently thedepending member [1, resulting in an action corresponding to the manualremoval and replacement of iron weights. Liquid such as water, issupplied to the bucket through a nozzle 38 at the lower end-of a pipe38'. The said pipe issupported in bearings 40 and 40' and its upper endis provided with a funnel to receive liquid preferably water from asupply pipe 48 having a valve 43'.

Means for guiding the water into the bucket may comprise a duplex funnel45 having compart- The compartment 46 is provided with an outlet 48positioned to discharge water into the bucket 3! and the compartment 41is provided with an outlet 4! to direct water to pipe 5| for passage toa waste pipe 52, said'pipe having a funnel-shaped opening 53 to receivewaste water from the bucket 31, said bucket being provided with anoutlet nozzle 54 controlled by a valve 55.

a An over-flow pipe 56 is also provided to direct any over-flow waterfrom the bucket to waste pipe 52. The nozzle 38 is oifset with respectto thepipe 38' so that a rotation of the pipe about its longitudinalaxis will move the nozzle over either of the compartments 46 or 41.Means for minates the flow of water to the bucket, permitting the waterto flow to waste and the bucket operates to hold the valve l6 open untilthe water has dripped from the bucket through the outlet 54.

\The foregoing description sets forth equipment including the source ofthe fuel and regulating means, also the means for indicating thevariations in the temperatureof a heat zone caused by the ignited fuel.

This equipment is shown in my patent referred to above andthe presentinvention is concerned with means for mechanically controlling theregulating. means in accordance with variations in temperature of theheat zone.

In carrying out the present invention I may use any suitable recordinginstrument and have selected a part of 9. Leeds and Northrup measuringand indicating apparatus such as disclosed in Reissue Patent 15,597.

As shown more clearly in Fig. 6 of the'drawings any suitable source ofpower may be em- 76 ployed as for example an electric motor 60preferably operable at a constant speed and having a worm BI on shaft62. The worm 6| is in mesh with worm wheel 93 on a horizontal shaft 64.The shaft 04 is provided with means to be later described for utilizinga recording mechanism, which mechanism comprises a lever 65 pivoted nearits upper end. At the rear of the lever member 65 and pivotallyconnected at 66 adjacent to the lower end thereof is a horizontal rockermember 61. The pivot point 60 is intermediate the ends of the rockermember 61 which ends are each provided with a shoe 68. The shoes arepreferably of cork or other suitable friction material to engage a rim,69 of what may be termed a clutch-disc or wheel 1I secured to one endof a shaft I2.

Secured upon the shaft 54 is a cam I3 which periodically engages thelever member 65 to move it outwardly away from the disc II, inopposition to a suitable spring, (not shown) thereby lifting the shoes68, 80 free from the rim 69 of the clutch disc II, the aforesaid springreturning the shoes 60, 68 into engagement with the rim 69 afterpredetermined rotation of the cam I3.

Upon the shaft 64 is secured a second cam 14 which, after the cam I3 haslifted the shoes 60, 60 from the rim 69, actuates a cam'follower I5 onthe lower end of an arm I6 secured at its upper end to a U-shaped memberI! arranged to rock about pivot points I0, I8 adjacent to the ends ofits arms. Mounted on the U-shapedmember 11 are what may be termed a pairof-lower gripper jaws I9, I0. These jaws are arranged with oppositelyinclined surfaces. Disposed immediately above the jaws I9 is a needle orpointer 32 of any suitable measuring or indicating instrument, as

for example, the galvanometer 3I of which 82 represents the movable coilor element which swings or deflects the needle or pointer 8| to theright or left.

At opposite ends of the jaws I9, I9 are abutments 03,- 93 for limitingthe degree of movement or swing of the needle 32. Directly above theneedle 32 and disposed over the path of movement of the needle, are whatmay be termed upper jaws 04, 84 so arranged that when the needle movesfrom its central position to either side, an actuation or relativemovement of the jaws will engage them with the needle.

Between the ends of the, respective pairs of jaws'a gap of sufllcientwidth is provided to allow the needle to raise when it is in balanced,zero or mid position. The jaws 84, 84 are pivoted at 05, 05. The needle32 normally swings freely between the lower edges of the jaws 04 and theupper edges of the jaws I9. Each of thejaws 84 is provided with adepending arm 86. These arms are normally urged toward each other by aspring 81. The arms 80 terminate in contact fingers 08, disposed forengagement with pins 09, 89 extending from a triangular plate 9Iattached to the lower end of the lever 65. Opposite ends of the arm 61are provided with ears or lugs 92, 92 adapted to be engaged by cams 93,93 similar in shape and similarly positioned and secured upon the shaft64. The shaft I2 is provided with a disc or wheel 94o! insulatingmaterail carrying on its periphery a resistance conductor 95 which maybe disposed in the form of a helix laid in a groove on the periphery ofthe disc 94. Engaging resistance 95 is a stationary contact member 96..This contact member serves in the operation of the recording mechanismdescribed, to restore a balance of electro-motive forces which tend todecrease the deflection of theneedle 32.

This operation is clearly described in the above .mentioned ReissuePatent 15,597 and it is believed that in the present description it isonly neces-' sary to generally indicate certain of the parts mounted onthe shaft I2, such as the wheel or disc 91 carrying on its peripheryresistances 98 and 99 of a Wheatstone bridge constituting a part of therecording construction.

The mechanism just described provides an apparatus wherein thevariations in the flow of electrical energy, by reason of differences intemperature cause the pointer 32 to oscillate. The movement of thepointer to either side results in its engagement between a pair of jaws84 and I9. When so engaged a rotation of the cam I4 causes a dependingarm 86 to rock and engage a pin 89 thus tipping'the lever member 61about its pivot point 66.

Inasmuch as the lever is normally urged to bring the shoes 60, 60against the disc II an adjustment of the lever or a change in itsposition about its fulcrum will leave it, when the shoes are engaged,with the disc ready to be moved accordingly about its axis and inasmuchas the disc is secured to shaft I2 the relative position of the contactmember 96 is changed and more or less resistance is cut in to theWheatstone bridge.

For the purpose of causing a return movement of the disc II the cams 93,93 are provided so that if the arm 61 is tipped and the shoesfrictionally engage the disc,a cam 93 will engage a lug 92 and move theshoe and consequently the disc I I with the result just described. Thismechanism therefore provides a shaft I2 which is rotated in oppositedirections in accordance with the oscillation of the needle 32.

- Whereas it has been proposed to employ the movement of the shaft suchas shaft I2 to operate' contact members for controlling a flow of energyto perform certain operations, the present invention utilizes themovement of the said shaft I2 to mechanically translate motion to meansfor controlling other mechanism. As hereinbefore mentioned the presentembodiment of the. invention includes apparatus for controlling the flowof a liquid to provide potential energy for actuating a regulator.

The liquid control mechanism comprises the pipe 38' rotatable about itslongitudinal axis in bearings 40 and 40. The said pipe 38' is providedwith arms -I III and I02 connected to ends of links I03 and I04respectively, which ends are disposed in slots I05, I in the arms. Theopposite ends of the links I03, I04 are connected with the ends of sliderods I00 and I01 respectively, movable in guide bearings I08, the otherends of the slide rods are connected by means of links I09 and III witharms H2 and H3 extending from lever-members H4 and H5 respectively.

The member H4 is pivoted at H6 and member H5 is pivoted at I". Themembers H4, H5 are arranged so that their arms I,I8, I I9 respectivelyare movable in opposite directions to cause a reverse movement of theiropposite arms I2I and I22, which latter arms constitute fingers normallyheld by a spring I23 against the surface of a cam I24. The ends of thearms H8, H9 are provided with rollers or cam followers I25 and I26respectively. The roller I25 is movable over the surface of a cam I21and the roller I26 is movable over asurface I28, the said cams beingadjustably mounted on a countershaft I29.

' ment 46.

The shaft I28 may be supported in suitable bearings I! and may beprovided with a bevel gear I32 in mesh with a bevel gear I33 at one endof a stub shaft I33. The stub shaft I33 may be provided with a bevelgear I34 in mesh with a bevel gear I35 on the shaft 54. The countershaftI29 is thus driven by the constantly driven shaft 64 and the gears maybe so proportioned that a rotation of the counter shaft is at a givennumber of revolutions per minute. In the present construction it ispreferable to rotate the cams I21, I 28 at about one revolution persecond.-

The cams I21, I28 are provided with drop portions I34 and I35respectively so that the cam followers which are held in contact withthe cam surfaces by spring I23 will be free to move toward or away fromeachother depending upon the variations in the surfaces of theirrespective cams.

As shown more clearly in Fig. 2 the arms I2I, I22 are provided withprojections or fingers I36 and I31 respectively which are normally heldby the spring I23 adjacent to surface I38 of the cam I 24, thepositionsof the fingers are however, determined by the positions of thecam followers I25, I26 as they travel over the cams I 21* and I 28. Whenthe said followers traverse the drop portions I34 and I35 of the camsI21, I28 the fingers I36 and I 31 will engage the surface I38 of camI24. When the cams I21, I28 move to position the cam followers I25, I26on the drop upon a slight rotary movement of the cam I24.

Considering the operation of thelever mem-.'

ber II 5, for example, it will be noted that the cam I28 will hold thefinger I 31 in position during a partial rotation of the cam I28 butwhen the cam follower I26 rides over the drop portion I35 of the cam,the finger I 31 will be free to move toward.

the cam I24. If at-this time the cam I24 has been rotated so as toposition the drop portion I33 of the cam I24 beneath the finger I31 thelever II5 will then move to actuate the arm II3 exerting apull on thelinks III, I81 and I84 and consequently move the end 38 of the liquidfeed pipe to position to discharge more liquid into the bucket 31. Ifthe cam I24 remains in position to allow the finger I31 to move towardthe center of the cam then a rotation of the cam I28 causes the rollerI26 to travel over the surface I35 to permit a movement of the fingerI31 toward the center of the cam I24. This movement of the fingertowards the link I84 acts to pull ,the arm I8I thus rocking the outlet38 over the compart The outlet or. nozzle 38 remains in thisposition tofeed liquid-to the weight chamber 31 and the lever member I I5 is freeto rock by reason of the slot I85 in the arm I8I. When thedisc I24 movesin an opposite direction the finger I31 periodically lifted by the camI28 again contacts with the surface I38 of the cam I24 while the fingerI38 drops inwardly toward the center of the cam causing the lever memberII4 to pull the arm I82 and thus move the nozzle 38 to position overcompartment 41 to let the liquid run to waste.

When in this position the finger I35 may be moved up and down by reasonof the rotation of the cam I21, the end of the link I83 being movable inthe slot I85 in the arm I82. The liquid then continues to run to wasteuntil the cam I24 is moved in an opposite direction and the foregoingoperations are repeated. Thus it will be seen that a movement of the camI24 serves tomechanically control the discharge of liquid either to thecompartment 46 and thus serving. to add to the weight 31 or to'compartment 41 from which the liquid runs to waste.

The recording mechanism shown in Fig. 6 serves to convert variations intemperature into mechanical movement through the agency of shaft 12 andthis movement is utilized by the present invention to operate means forcontrol-. ling other mechanism, as for example a gas regulator or foroperating a mercury switch, as shown in Fig. 5. In'this figure a mercuryswitch I43 is shown pivoted at I44. The switch may have a pair of arms I45 and I46 connected to links I83 and I84 so that the switch will betilted to make and break internal electrodes connected with conductorsI41 and I48. Any suitable type of mercury switch may be used and as theinternal constructions thereof are well known the same is not describedherein. With the mechanism including the switch I43 it is possible toregulate a fiow of electrical energy as for example if an electricalfurnace is used thus actuating the switch in accordance with temperaturevariation of the furnace the temperature may be held constant within agiven range.

From the foregoing description it will be evi-. dent that an extremelyfine degree of regulation may be had when utilizing the presentapparatus and as shown in Fig. 2 the cam I24 may be so adjusted that agiven movement thereof will be required before the fingers operate. Forex- 7 ample, the cam may be adjusted for a given temperature so that onefinger operates continually to hold the nozzle in a given position, asfor example, to feed liquid to waste, thus allowing the.

gree, thus permitting the cam to be moved until the surface I38 of thedisc becomes engaged by the finger I36. If a variation in temperatureagain occurs the finger I31 drops causing the nozzle 38 to be moved todischarge liquid to supply weight to the container 31. When thistemperature is reached it will be held constant since the mechanism willthen operate to adjust the nozzle in accordance with any variation intemperature as above described.

If desirable the movement of the shaft 12 may be amplified and for thispurpose a belt I49, as shown in Fig. 7, may be employed leading from apulley I5I on a counter shaft I52 and around a pulley I53 on the shaft12. With this construction the movement of the shaft when translated tothe cam I24 is multiplied allowing for more convenient and accurateadjustment.

By reason of the above mechanism, it is possible to get a more completedegree of sensitivity in the temperature regulation of the heat zone tobe controlled. For example, the cam I38 may be moved sufiic'iintly todrop one of the fingers I36, I31 upon a minute movement of the pulleyI53 which pulley is actuated by the member 1 I; the member 1I beingactuated in accordance with the variation in the temperature of the heatzone under control. By reason of theamplifled or relacontinuouslyrotating cams duced by an electric When the present invention isemployed to control the temperature and length of a gas flame, inaccordance with the practical embodiment of the invention shown, v gasmay be supplied through the conductor III to various parts of abuilding, and connected by suitable conduits with burners such as 2I toproduce flames 22 for glass work parts. For the purpose of controllingthe temperature of the gas flames, a standard flame 25 is employed. Thisflame is directed against a baffle 26 and a heat zone is produced. Anelectron thermo couple 21 is disposed in and is responsive to variationsin the temperature of the heat zone.

The variations in temperature so affect the thermo couple that theneedle 32 of the indicating instrument 3| to which the thermo couple isconnected is caused to oscillate in accordance with the variations inthe electromotive force in the thermo couple circuit. A movement of theneedle or pointer 32 indicates a variation in the temperature or lengthof the flame 25 and by reason of the cooperating mechanism including thejaws 19-49 and 84-84 as shown in Figure 6, the pointer serves to operatemechanism which rotates a disc 1| and consequently the shaft 12 ineither a clockwise or counter clockwise direction.

The end of the shaft 12 opposite to that secured to the disc 1 I, isprovided with a movable element in the form of a cam I24 which is soarranged as to have its larger or raised portion normally positioned toengage the ends or fingers I2I and I22 of the lever or rod or arms H2and H3. These fingers are urged toward the cam by the spring I23 but theopposite ends of the arms engage the I21 and I28 on the shaft I29 sothat the fingers may drop against the cam I24 periodically as the camsrotate.

when the cam I24 moves by reason ofthe oscil lation of the pointer 32,then one of the fingers will drop as a cam I21 or I28 moves to permitits contacting cam follower to travel over the reduced portion of thecam it is following. This movement causes a pull on one of the links I04or I03 causing the nozzle 38 to either supply water to thecounter-balancing bucket 31 to regulate flow of gas through the pipeIII, or to discharge water to waste permitting the fiow of gas throughthe pipe III without further regulation.

It will be evident that the movement produced by reason of the action ofthe fingers I36 and I31 may be employed for various purposes. Thepresent invention is particularly adapted for controlling the supply ofheat in accordance with variations in the temperature of a heatzoneproheater, since the instrumentalities disclosed, by reason of thepresent invention, serve to convert temperature variations intomechanical movements which are utilized to regulate the source of heatsupply and thus maintain a heat zone at a predetermined temperature.

Altho a preferred embodiment of the invention is shown and describedherein, it should be understood that various modifications may be madetherein without departing from the scope and spirit of the invention asset forth in the annexed claims.

a fiuid such as illuminating I21 and I23 What is claimed is:

1. A device for regulating the temperature of a. heat zone, acam-member, means for rotating said cam clockwise or counter-clockwisein accordance with temperature variations in said zone, a pair of levermembers having ends engageable with said cam, a second cam member, meansfor rotating said second cam, means for holding the other ends of saidlever members en gaged with said second cam, an arm extendingsubstantially transversely from each of said 1evers, a movable elementfor controlling the temperature of said heat zone and means connectingsaid element with said means.

2. In an apparatus having a member movable in accordance with variationsin the temperature of a heat zone the combination with a continuouslydriven member, a pivoted member having one end engageable with saidcontinuously movable member, and the other end engageable with saidfirst mentioned member, means operable upon a movement of said firstmentioned member to rock said pivoted member, another movable member andmeans connecting said last named member with said pivoted member.

3. In an apparatus having a shaft movable upon variations in thetemperature of a heat zone,- a movable element, a pair of oppositelymovable pivoted members for translating motion from said shaft to saidelement, means for intermittently moving said members and means on saidshaft for controlling the degree of movement of said members.

4. In an apparatus having a shaft movable upon variations in thetemperature of a heat zone, a movable element, a movable memberintermediate said shaft and said element for translating motion fromsaid shaft to said element,

' means on said shaft controlling the movement of said member, and meansfor intermittently moving said member into operative relation with saidfirst mentioned means.

5. In an apparatus of the class described, a disk having a high and alow surface, means for moving the disk clockwise or counter clockwise inaccordance with variations in the temperature of a heat zone, a rockerarm, means for moving said arm into and out of operative relation withsaid disk to engage a high or low surface thereof whereby the degree ofmovement of said arm is varied, an electrical circuit and meansoperating under the action of said arm to open or close said circuit.

'6. In an apparatus of the oscillatory member, a member having contactsurfaces in different planes movable in accordance with temperaturevariations in a heat zone, means for oscillating said member to cause itto move into and out of surfaces of said member, a movable element, andmeans for translating movement from said oscillatory member to saidelement.

'1. In an apparatus of the class described, a shaft movable inaccordance with the variations in the temperature of a heat zone, amember for controlling the temperature of said zone, a rocker arm, meansfor actuating said member when said arm moves a predetermined distance,a continuously driven member for moving said arm and means on said shaftfor limiting the degree of movement of said arm.

8. In an apparatus of the class described, a shaft movable in accordancewith the variations in the temperature of a heat zone, a member forcontrolling the temperature of said zone,

contact relation with the a rocker arm, means for actuating said memberwhen said arm moves a predetermined distance, a continuously drivenmember for moving said arm, means on said shaft for limiting the degreeof movement of said arm, and means for adjusting said last mentionedmeans to varying the degree of movement of said arm to vary the relativemovement of the member for controlling the temperature of said zone.

9. In. an apparatus or the class described. means movable in accordancewith variations in the temperature of a heat zone, a cam platehavingportions of its cam surface of diiferent diametrical' i dimensionsmovable with said means, a pivoted member having one end in contact withthe greater dimensioned cam surface. a continuously driven member forurging said end against said-cam, a movable member for ying thetemperature of said heat zone, means connecting said member with saidpivoted member to cause an actuation of said movable member upon amovement of said pivoted I member when said cam moves to remove thegreater dimensioned portion of said cam from contact with the end ofsaidpivoted member.

10. In anapparatus of the class described,

' means movable in accordance with the temperature of a heat zone, a camplate having portions of its cam surface of diiierent diametricaidbmensions movable with member having one end in contact with the greaterdimensioned cam surface, a continuously driven member for urging saidend against said cam, a movable member for varying the temperature ofsaid heat zone, means connecting said member with said pivoted member tocause an actuation of said movable member upon a movement of saidpivoted member when said cam moves to remove the greater dimensionedportion of said cam from contact with the end of'said pivoted member,and means for adjusting said cam to vary the degree of movementnecessary to cause the end of said pivoted memfaoes, a movable elementand means for translating motion from said arm to said element.

' LANDON R. CALVERT.

said means, a pivoted to said lesser dimensioned portion

